Better fix to set the palette opaque, when there is also a colorkey

(see bug 3827)
This commit is contained in:
Sylvain Becker 2020-02-24 21:57:03 +01:00
parent e3b0713e40
commit e2b132ca74

View File

@ -402,64 +402,6 @@ SDL_ConvertColorkeyToAlpha(SDL_Surface * surface, SDL_bool ignore_alpha)
SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_BLEND); SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_BLEND);
} }
static void
SDL_ConvertSetOpaque(SDL_Surface * surface)
{
int x, y;
if (!surface) {
return;
}
if (!surface->format->Amask) {
return;
}
SDL_LockSurface(surface);
switch (surface->format->BytesPerPixel) {
case 2:
{
Uint16 *row, *spot;
Uint16 mask = (Uint16) (surface->format->Amask);
row = (Uint16 *) surface->pixels;
for (y = surface->h; y--;) {
spot = row;
for (x = surface->w; x--;) {
*spot |= mask;
++spot;
}
row += surface->pitch / 2;
}
}
break;
case 3:
/* FIXME */
break;
case 4:
{
Uint32 *row, *spot;
Uint32 mask = surface->format->Amask;
row = (Uint32 *) surface->pixels;
for (y = surface->h; y--;) {
spot = row;
for (x = surface->w; x--;) {
*spot |= mask;
++spot;
}
row += surface->pitch / 4;
}
}
break;
}
SDL_UnlockSurface(surface);
}
int int
SDL_SetSurfaceColorMod(SDL_Surface * surface, Uint8 r, Uint8 g, Uint8 b) SDL_SetSurfaceColorMod(SDL_Surface * surface, Uint8 r, Uint8 g, Uint8 b)
{ {
@ -1023,6 +965,7 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
SDL_bool palette_ck_transform = SDL_FALSE; SDL_bool palette_ck_transform = SDL_FALSE;
int palette_ck_value = 0; int palette_ck_value = 0;
SDL_bool palette_has_alpha = SDL_FALSE; SDL_bool palette_has_alpha = SDL_FALSE;
Uint8 *palette_saved_alpha = NULL;
if (!surface) { if (!surface) {
SDL_InvalidParamError("surface"); SDL_InvalidParamError("surface");
@ -1084,6 +1027,40 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
bounds.w = surface->w; bounds.w = surface->w;
bounds.h = surface->h; bounds.h = surface->h;
/* Source surface has a palette with no real alpha (0 or OPAQUE).
* Destination format has alpha.
* -> set alpha channel to be opaque */
if (surface->format->palette && format->Amask) {
SDL_bool set_opaque = SDL_FALSE;
{
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
Uint8 alpha_value = surface->format->palette->colors[i].a;
if (alpha_value != 0 && alpha_value != SDL_ALPHA_OPAQUE) {
/* Palette has at least one alpha value. Don't do anything */
set_opaque = SDL_FALSE;
palette_has_alpha = SDL_TRUE;
break;
}
if (alpha_value == 0) {
set_opaque = SDL_TRUE;
}
}
}
/* Set opaque and backup palette alpha values */
if (set_opaque) {
palette_saved_alpha = SDL_stack_alloc(Uint8, surface->format->palette->ncolors);
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
palette_saved_alpha[i] = surface->format->palette->colors[i].a;
surface->format->palette->colors[i].a = SDL_ALPHA_OPAQUE;
}
}
}
/* Transform colorkey to alpha. for cases where source palette has duplicate values, and colorkey is one of them */ /* Transform colorkey to alpha. for cases where source palette has duplicate values, and colorkey is one of them */
if (copy_flags & SDL_COPY_COLORKEY) { if (copy_flags & SDL_COPY_COLORKEY) {
if (surface->format->palette && !format->palette) { if (surface->format->palette && !format->palette) {
@ -1096,11 +1073,20 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
ret = SDL_LowerBlit(surface, &bounds, convert, &bounds); ret = SDL_LowerBlit(surface, &bounds, convert, &bounds);
/* Restore value */ /* Restore colorkey alpha value */
if (palette_ck_transform) { if (palette_ck_transform) {
surface->format->palette->colors[surface->map->info.colorkey].a = palette_ck_value; surface->format->palette->colors[surface->map->info.colorkey].a = palette_ck_value;
} }
/* Restore palette alpha values */
if (palette_saved_alpha) {
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
surface->format->palette->colors[i].a = palette_saved_alpha[i];
}
SDL_stack_free(palette_saved_alpha);
}
/* Clean up the original surface, and update converted surface */ /* Clean up the original surface, and update converted surface */
convert->map->info.r = copy_color.r; convert->map->info.r = copy_color.r;
convert->map->info.g = copy_color.g; convert->map->info.g = copy_color.g;
@ -1181,38 +1167,6 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
} }
SDL_SetClipRect(convert, &surface->clip_rect); SDL_SetClipRect(convert, &surface->clip_rect);
/* Source surface has a palette with alpha. Will need blend mode */
if (palette_has_alpha == SDL_FALSE && surface->format->palette) {
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
Uint8 alpha_value = surface->format->palette->colors[i].a;
if (alpha_value != 0 && alpha_value != SDL_ALPHA_OPAQUE) {
palette_has_alpha = SDL_TRUE;
break;
}
}
}
/* Source surface has a palette with no alpha nor colorkey.
* Destination format has alpha.
* We may need to set the alpha channel to opaque. */
if (surface->format->palette && format->Amask && palette_has_alpha == SDL_FALSE) {
SDL_bool need_opaque = SDL_FALSE;
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
Uint8 alpha_value = surface->format->palette->colors[i].a;
if (alpha_value == 0) {
need_opaque = SDL_TRUE;
break;
}
}
if (need_opaque) {
SDL_ConvertSetOpaque(convert);
}
}
/* Enable alpha blending by default if the new surface has an /* Enable alpha blending by default if the new surface has an
* alpha channel or alpha modulation */ * alpha channel or alpha modulation */
if ((surface->format->Amask && format->Amask) || if ((surface->format->Amask && format->Amask) ||